Apparatus for efficient removal of halogen residues from etched substrates

ABSTRACT

An apparatus for removing volatile residues from a substrate is provided. In one embodiment, an apparatus for removing halogen-containing residues from a substrate includes a chamber suitable for operating maintaining a vacuum therein and a heat module positioned to heat a substrate disposed in the chamber. The apparatus for removing halogen-containing residues from a substrate also includes at least one of A) a temperature controlled pedestal having a projection extending radially therefrom suitable for supporting the temperature control pedestal on a ledge of the chamber body, the projection thermally isolating the base from the chamber body; B) a pair of substrate holders that include two support flanges extending radially inward from an inner edge of an arc-shaped body, each support flange having a substrate support step that includes a sloped landing; or C) a domed window.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit to U.S. Provisional Patent ApplicationSer. No. 61/103,435, filed Oct. 7, 2008, which is incorporated byreference in its entirety.

This application is related to U.S. patent application Ser. No.11/553,132, filed Oct. 26, 2006, U.S. patent application Ser. No.11/676,161, filed Feb. 16, 2007, and U.S. patent application Ser. No.12/201,170, filed Aug. 29, 2008. All the above applications areincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an apparatus for fabricatingdevices on a semiconductor substrate. More specifically, the presentinvention relates to an apparatus for removing halogen-containingresidues after plasma etching a layer on a semiconductor substrate.

2. Description of the Related Art

Ultra-large-scale integrated (ULSI) circuits may include more than onemillion electronic devices (e.g., transistors) that are formed on asemiconductor substrate, such as a silicon (Si) substrate, and cooperateto perform various functions within the device. Typically, thetransistors used in the ULSI circuits are complementarymetal-oxide-semiconductor (CMOS) field effect transistors. A CMOStransistor has a gate structure comprising a polysilicon gate electrodeand gate dielectric, and is disposed between a source region and drainregions that are formed in the substrate.

Plasma etching is commonly used in the fabrication of transistors andother electronic devices. During plasma etch processes used to formtransistor structures, one or more layers of a film stack (e.g., layersof silicon, polysilicon, hafnium dioxide (HfO₂), silicon dioxide (SiO₂),metal materials, and the like) are typically exposed to etchantscomprising at least one halogen-containing gas, such as hydrogen bromide(HBr), chlorine (Cl₂), carbon tetrafluoride (CF₄), and the like. Suchprocesses cause a halogen-containing residue to build up on the surfacesof the etched features, etch masks, and elsewhere on the substrate.

When exposed to a non-vacuumed environment (e.g., within factoryinterfaces or substrate storage cassettes) and/or during consecutiveprocessing, gaseous halogens and halogen-based reactants (e.g., bromine(Br₂), chlorine (Cl₂), hydrogen chloride (HCl), and the like) may bereleased from the halogen-containing residues deposited during etching.The released halogens and halogen-based reactants create particlecontamination and cause corrosion of the interior of the processingsystems and factory interfaces, as well as corrosion of exposed portionsof metallic layers on the substrate. Cleaning of the processing systemsand factory interfaces and replacement of the corroded parts is a timeconsuming and expensive procedure.

Several processes have been developed to remove the halogen-containingresidues on the etched substrates. For example, the etched substrate maybe transferred into a remote plasma reactor to expose the etchedsubstrate to a gas mixture that converts the halogen-containing residuesto non-corrosive volatile compounds that may be out-gassed and pumpedout of the reactor. However, such process requires a dedicated processchamber along with an additional step, causing increased tool expense,reduced manufacturing productivity and throughput, resulting in highmanufacturing cost.

Therefore, there is a need for an improved apparatus for removinghalogen-containing residues from a substrate.

SUMMARY OF THE INVENTION

An apparatus for removing volatile residues from a substrate isprovided. In one embodiment, an apparatus for removinghalogen-containing residues from a substrate includes a chamber suitablefor operating maintaining a vacuum therein and a heat module positionedto heat a substrate disposed in the chamber. The apparatus for removinghalogen-containing residues from a substrate also includes at least oneof A) a temperature controlled pedestal having a projection extendingradially therefrom suitable for supporting the temperature controlpedestal on a ledge of the chamber body, the projection thermallyisolating the base from the chamber body; B) a pair of substrate holdersthat include two support flanges extending radially inward from an inneredge of an arc-shaped body, each support flange having a substratesupport step that includes a sloped landing; or C) a domed windowdisposed through a lid of the chamber.

In other embodiments, methods for removing volatile residues on anetched substrate are provided. In one embodiment, a method for removingvolatile residues from a substrate includes providing a processingsystem having a load lock chamber and at least one processing chambercoupled to a transfer chamber, treating a substrate in the processingchamber with a chemistry comprising halogen, and removing volatileresidues from the treated substrate in the load lock chamber, partiallycooling the substrate in the load lock chamber while venting, andcooling the substrate removed from the load lock chamber on a substrateholder in a factory interface prior to returning the substrate to aFOUP.

In another embodiment, a method for removing volatile residues from asubstrate includes providing a processing system having a load lockchamber and at least one processing chamber coupled to a transferchamber, treating a substrate in the processing chamber with a chemistrycomprising halogen, and removing volatile residues from the treatedsubstrate in the load lock chamber.

In another embodiment, a method for removing halogen-containing residuesfrom a substrate includes providing a processing system having a loadlock chamber and at least one processing chamber coupled to a transferchamber, treating a substrate in the processing chamber with chemistrycomprising halogen, removing halogen-containing residues from thesubstrate in the load lock chamber, and subsequently cooling thesubstrate in the load lock chamber.

In another embodiment, an apparatus suitable for removinghalogen-containing residues from a substrate includes at least one etchchamber, a load lock chamber interfaced with a heat module that isadapted to heat a substrate disposed in the load lock chamber, atransfer chamber having a robot disposed therein that is adapted totransfer the substrate between the etch chamber and the load lockchamber, a remote plasma source coupled to the load lock chamber.

In yet another embodiment, a domed window is provided. The domed windowmay include a convex member coupled to a ring. The ring includes anoutside edge, an inside edge opposite the outside edge, and a lip. Thelip is angled upward and extends radially inward from the inside edge.The lip is sealingly coupled to the outer edge of the convex member.

In yet another embodiment, a pedestal is provided. The pedestal includesa cooling coil disposed in a recess adjacent a bottom surface of a base.The base includes an outer wall, a projection extending radially fromthe outer wall, a top surface, a mounting feature positioned centrallywithin the base, and a countersink formed on the top surface of thebase. The mounting feature has an aperture configured to accept anoptical termination from the top surface. The countersink is configuredto permit the entry of light into the aperture.

In yet another embodiment, a substrate holder is provided. The substrateholder includes an arc-shaped body having a mounting flange extendingradially outward from an outer edge of the holder. Two support flangesare positioned at opposite ends of the body. Each support flange extendsradially inward from an inner edge of the body and has a substratesupport step recessed from a top side of the body. Each substratesupport step has a sloped landing.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 depicts a schematic diagram of an exemplary processing apparatusthat includes one embodiment of a load lock chamber suitable forpractice the present invention;

FIG. 1A depicts a partial sectional view of one embodiment of anexemplary pass through station of the processing apparatus of FIG. 1;

FIG. 2 depicts a sectional view of a load lock chamber utilized in FIG.1;

FIG. 3 depicts a sectional view of one embodiment of a heater module;

FIG. 4 depicts a sectional view of another embodiment of a load lockchamber;

FIG. 5 depicts a process diagram illustrating a method for removinghalogen-containing residues on a substrate according to one embodimentof the present invention;

FIG. 6 depicts a sectional view of one embodiment of a window that maybe utilized in the load lock chamber of FIG. 2, among other vacuumchambers;

FIG. 7 depicts a sectional view of one embodiment of a temperaturecontrol pedestal that may be utilized in the load lock chamber of FIG.2, among other vacuum chambers;

FIG. 8 is a partial sectional view of the temperature control pedestalof FIG. 7 illustrating a substrate spacer;

FIG. 9 is another partial sectional view of the temperature controlpedestal of FIG. 7 illustrating an optics termination;

FIG. 10 depicts a perspective view of one embodiment of a substrateholder that may be utilized in the load lock chamber of FIG. 2, amongother vacuum chambers;

FIG. 11 depicts a top plan view of the substrate holder of FIG. 10; and

FIG. 12 is a partial sectional view of the substrate holder of FIG. 10.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

It is to be noted, however, that the appended drawings illustrate onlyexemplary embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

DETAILED DESCRIPTION

The present invention provides a method and apparatus for removinghalogen-containing residues from a substrate etched using an etchantthat includes halogen. In one embodiment, the halogen-containingresidues deposited during substrate etching are removed by a thermaltreatment process performed in a load lock chamber integrated within aprocessing system. The load lock chamber heats the etched substrate andconverts the halogen-containing residues into non-volatile compoundswhich may be pumped out of the load lock chamber. By performing thehalogen-containing residue removal process in the load lock chamberduring the substrate transfer sequence through the load lock chamber,the residue is removed without adversely increasing the overall processcycle time. The invention substantially prevents the environment of theprocessing system and the substrate from contamination and corrosionwhile maintaining high productivity and process throughput.

FIG. 1 is a schematic, top plan view of an exemplary processing system100 that includes one embodiment of a load lock chamber 122 suitable forpracticing the present invention. In one embodiment, the processingsystem 100 may be a CENTURA® integrated processing system, commerciallyavailable from Applied Materials, Inc., located in Santa Clara, Calif.It is contemplated that other processing systems (including those fromother manufacturers) may be adapted to benefit from the invention.

The system 100 includes a vacuum-tight processing platform 104, afactory interface 102, and a system controller 144. The platform 104includes a plurality of processing chambers 110, 112, 132, 128, 120 andat least one load-lock chamber 122 that are coupled to a vacuumsubstrate transfer chamber 136. Two load lock chambers 122 are shown inFIG. 1. The factory interface 102 is coupled to the transfer chamber 136by the load lock chambers 122.

In one embodiment, the factory interface 102 comprises at least onedocking station 108 and at least one factory interface robot 114 tofacilitate transfer of substrates. The docking station 108 is configuredto accept one or more front opening unified pod (FOUP). Two FOUPS 106A-Bare shown in the embodiment of FIG. 1. The factory interface robot 114having a blade 116 disposed on one end of the robot 114 is configured totransfer the substrate from the factory interface 102 to the processingplatform 104 for processing through the load lock chambers 122. Twointerface robots 114 are shown in FIG. 1. Optionally, one or moremetrology stations 118 may be connected to a terminal 126 of the factoryinterface 102 to facilitate measurement of the substrate from the FOUPS106A-B.

As additionally shown in FIG. 1 and FIG. 1A, the factory interface 102includes a pass-through station 180 to facilitate handoff between theload lock chambers 122. The pass-through station 180 includes asubstrate holder 182 which is configured to retain one or moresubstrates in a manner that allows a substrate to be placed andretrieved by either of the robots 114. In one embodiment, the holder 182includes two substrate support flanges 184. Each substrate supportflanges 184 has an arc shaped ledge 186 configured to retain an edge ofthe substrate thereon.

The substrate holder 182 may also be used as a queuing station to allowsubstrates to cool after retaining from the load lock chamber 122 andprior to being placed in the FOUPS 106A-B. For example, a processedsubstrate may be cooled in the load lock chamber 122 down to firsttemperature while venting the load lock chamber which is too great to beplaced in the FOUP. The still hot substrate may then be placed in thesubstrate holder 182 for a predetermined period of time until thesubstrate reaches a second temperature which is low enough to be placedin the FOUP. In one embodiment, the substrate is set in the substrateholder 182 to cool for about 20-30 second. During that time, the loadlock chamber 122 may be utilized to pass another substrate into thetransfer chamber 136 for processing. Since the load lock chamber 122 isfreed from having to completely cool the substrate to the secondtemperature, less time is utilized to remove substrates from thetransfer chamber 136 to the factory interface 102. Accordingly, thenumber of substrates which can be passed through the load lock chamber122 is advantageously increased. Additionally, the use of two or moresubstrate holders 182 allow at least one substrate to be cooled whilemaintaining a free holder 182 to allow substrate exchange between therobots 114.

In one embodiment, the pass-through station 180 is supported by a crossmember 194 spanning between the walls of the factory interface 102. Thepass-through station 180 may be located below the cross member 194, thusallowing space for a substrate orientation module to be mounted abovethe cross member 194. The substrate orientation, as conventionallyknown, includes a turntable 190 and sensor 192 for finding notches,flats or other indicia of the substrate's orientation.

A flow shield 154 may be mounted to the cross member 194 above thesubstrate holders 182. The flow shield 154 has a diameter greater thanthat of the substrates positioned in the substrate holders 182, wherebyallowing the flow shield 154 to block flow (as indicated by arrows 152)provided by particulate air filters 150 positioned in the ceiling of thefactory interface 102 to minimize potential contamination of thesubstrates positioned in the substrate holders 182 while cooling.

Referring back to FIG. 1, each of the load lock chambers 122 have afirst port coupled to the factory interface 102 and a second portcoupled to the transfer chamber 136. The load lock chambers 122 arecoupled to a pressure control system (not shown) which pumps down andvents the load lock chambers 122 to facilitate passing the substratebetween the vacuum environment of the transfer chamber 136 and thesubstantially ambient (e.g., atmospheric) environment of the factoryinterface 102.

The transfer chamber 136 has a vacuum robot 130 disposed therein. Thevacuum robot 130 has a blade 134 capable of transferring substrates 124between the load lock chambers 122 and the processing chambers 110, 112,132, 128, 120.

In one embodiment, at least one process chambers 110, 112, 132, 128, 120is an etch chamber. For example, the etch chamber may be a DecoupledPlasma Source (DPS) chamber available from Applied Materials, Inc. TheDPS etch chamber uses an inductive source to produce high-density plasmaand comprises a source of radio-frequency (RF) power to bias thesubstrate. Alternatively, at least one of the process chambers 110, 112,132, 128, 120 may be one of a HART™, E-MAX®, DPS®, DPS II, PRODUCER E,or ENABLER® etch chamber also available from Applied Materials, Inc.Other etch chambers, including those from other manufacturers, may beutilized. The etch chambers, for example, chambers 110, 112, 132, 128,120 may use a halogen-containing gas to etch the substrate 124 therein.Examples of halogen-containing gas include hydrogen bromide (HBr),chlorine (Cl₂), carbon tetrafluoride (CF₄), and the like. After etchingthe substrate 124, halogen-containing residues may be left on thesubstrate surface. The halogen-containing residues may be removed by athermal treatment process in the load lock chambers 122, as will befurther discussed below.

The system controller 144 is coupled to the processing system 100. Thesystem controller 144 controls the operation of the system 100 using adirect control of the process chambers 110, 112, 132, 128, 120 of thesystem 100 or alternatively, by controlling the computers (orcontrollers) associated with the process chambers 110, 112, 132, 128,120 and the system 100. In operation, the system controller 144 enablesdata collection and feedback from the respective chambers and systemcontroller 144 to optimize performance of the system 100.

The system controller 144 generally includes a central processing unit(CPU) 138, a memory 140, and support circuit 142. The CPU 138 may be oneof any form of a general purpose computer processor that can be used inan industrial setting. The support circuits 142 are conventionallycoupled to the CPU 138 and may comprise cache, clock circuits,input/output subsystems, power supplies, and the like. The softwareroutines, such as a method 500 for removing halogen-containing residuesdescribed below with reference to FIG. 5, when executed by the CPU 138,transform the CPU 138 into a specific purpose computer (controller) 144.The software routines may also be stored and/or executed by a secondcontroller (not shown) that is located remotely from the system 100.

FIG. 2 depicts one embodiment of the load lock chamber 122 utilized toperform a halogen-containing residue removal process. The load lockchamber 122 generally comprises a chamber body 202, a first substrateholder 204, a second substrate holder 206, a temperature controlpedestal 240 and a heater module 270. The chamber body 202 may befabricated from a singular body of material such as aluminum. Thechamber body 202 includes a first side wall 208, a second side wall 210,lateral walls (242 in FIG. 3), a top 214 and a bottom 216 that define achamber volume 218. A window 250 (shown in FIG. 4) typically comprisedof quartz, is disposed in the top 214 of the chamber body 202 and is atleast partially covered by the heater module 270. Another embodiment ofa window is described below with reference to FIG. 6.

The pressure of the chamber volume 218 may be controlled so that theload lock chamber 122 may be evacuated to substantially match theenvironment of the transfer chamber 136 and be vented to substantiallymatch the environment of the factory interface 102. Additionally, thepressure of the chamber volume 218 may be controlled within apredetermined range that facilitates performing the halogen-containingresidues removal process, as further described below. The chamber body202 includes one or more vent passages 230 and a pump passage 232. Thevent passage 230 and the pump passage 232 are positioned at oppositeends of the chamber body 202 to induce laminar flow within the chambervolume 218 during venting and evacuation to minimize particulatecontamination. In one embodiment, two vent passages 230 are disposedthrough the top 214 of the chamber body 202, while the pump passage 232is disposed through the bottom 216 of the chamber body 202. The passages230, 232 typically are coupled to a valve 212 to selectively allow flowinto and out of the chamber volume 218. Alternatively, the passages 230,232 may be positioned at opposite ends of one of the chamber walls, oron opposing or adjacent walls. In one embodiment, the vent passage 230is coupled to a high efficiency air filter 236 such as available fromCamfil Farr, Inc., of Riverdale, N.J.

The vent passage 230 may be additionally coupled to a gas source 252through a valve 241 to provide a gas mixture into the chamber volume218. In one embodiment, the vent passage 230 may be configured as a gasdistribution ring wherein the gas mixture may be distributed fromadjacent the walls 210, 208 through an array of holes to optimize theflow uniformity. In another embodiment, the gas mixture may be suppliedto the load lock chamber 122 through a gas distribution plate (notshown) disposed below the heater module 270. The gas distribution platemay be fabricated by a material transmissive to the heat generated fromthe heater module 270 such as not to substantially interfere with theheating of the substrates positioned on the substrate holders 204, 206.Examples of gases that may be supplied from the gas source 252 includenitrogen (N₂), argon (Ar), hydrogen (H₂), alkanes, alkenes, helium (He),oxygen (O₂), ozone (O₃), wafer vapor (H₂O), and the like.

In one embodiment, a remote plasma source (RPS) 248 may be alternativelycoupled to the vent passage 230 to assist in removing thehalogen-containing residues from the substrate surfaces. The remoteplasma source 248 provides plasma formed from the gas mixture providedby the gas source 252 to the load lock chamber 122. In embodiment theremote plasma source (RPS) 248 is present, a diffuser (not shown) may bedisposed at the outlet of the vent passage 230 to facilitate deliverythe generated plasma into the load lock chamber 122.

The pump passage 232 is coupled to a point-of-use pump 236, such asavailable from Alcatel, headquartered in Paris, France. The point-of-usepump 236 has low vibration generation to minimize the disturbance of thesubstrate 124 positioned on the holders 204, 206 within the load lockchamber 122 while promoting pump-down efficiency and time by minimizingthe fluid path between the load lock chamber 122 and pump 236 togenerally less than three feet.

A first loading port 238 is disposed in the first wall 208 of thechamber body 202 to allow the substrate 124 to be transferred betweenthe load lock chamber 122 and the factory interface 102. A first slitvalve 244 selectively seals the first loading port 238 to isolate theload lock chamber 122 from the factory interface 102. A second loadingport 239 is disposed in the second wall 210 of the chamber body 202 toallow the substrate 124 to be transferred between the load lock chamber122 and the transfer chamber 136. A second slit valve 246 which issubstantially similar to the first slit valve 244 selectively seals thesecond loading port 239 to isolate the load lock chamber 122 from thevacuum environment of the transfer chamber 136.

The first substrate holder 204 is concentrically coupled to (i.e.,stacked on top of) the second substrate holder 206 that is disposedabove the chamber bottom 216. The substrate holders 204, 206 aregenerally mounted to a hoop 220 that is coupled to a shaft 282 thatextends through the bottom 216 of the chamber body 202. Typically, eachsubstrate holder 204, 206 is configured to retain one substrate. Theshaft 282 is coupled to a lift mechanism 296 disposed exterior to theload lock chamber 122 that controls the elevation of the substrateholders 204, 206 within the chamber body 202. A bellows 284 is coupledbetween the hoop 220 and the bottom 216 of the chamber body 202 anddisposed around the shaft 282 to provide a flexible seal between thesecond substrate holder 206 and the bottom 216, thus preventing leakagefrom or into the chamber body 202 and facilitating raising and lowing ofthe substrate holders 204, 206 without compromising the pressure withinthe load lock chamber 122.

The first substrate holder 204 is utilized to hold an unprocessedsubstrate from the factory interface 102 while the second substrateholder 206 is utilized to hold a processed substrate (e.g., an etchedsubstrate) returning from the transfer chamber 136. The flow within theload lock chamber 122 during venting and evacuation is substantiallylaminar due to the position of the vent passage 230 and pump passage 232and is configured to minimize particulate contamination.

FIG. 3 depicts one embodiment of the substrate holders 204, 206 in theload lock chamber 122. The second substrate holder 206 is generally heldabove the bottom 216 of the chamber body 202 by the hoop 220. A firststandoff 308 is disposed between each member 304, 306 to maintain thesecond substrate holder 206 in a spaced-apart relation to the hoop 220.A second standoff 310 is disposed between the first and second substrateholders 204, 206 to maintain a spaced-apart relation therebetween. Thestandoffs 308, 310 allow blades 134, 116 of the transfer and factoryinterface robots 130, 114 to pass therebetween when retrieving anddepositing substrates on the substrate holders 204, 206. Each substrateholder 204, 206 includes a first member 304 and a second member 306.Each holder 204, 206 may have alternatively include a “L-shaped”configuration that incorporates a portion that maintains a spaced-apartrelation between holder 204, 206 and adjacent components of the loadlock chamber 122.

Each member 304, 306 includes a curved inner portion 312 that has a lip314 extending radially inwards therefrom. The curved inner portion 312is generally configured to allow the substrate 124 to pass therebetweenand rest on the lip 314. The curved inner portion 312 captures thesubstrate 124 therebetween, thus preventing the substrate 124 fromfalling off the lip 314.

Referring back to FIG. 2, the temperature control pedestal 240 iscoupled to the bottom 216 of the chamber body 202 by a support 278. Thesupport 278 may be hollow or include passages therethrough to allowfluids, electrical signals, sensor and the like to be coupled to thepedestal 240. Alternatively, the pedestal 240 may be movably coupled tothe chamber body 202 by a second shaft 282A and lift mechanism 296A. Inthat embodiment, the support 278 may include a bellows 284.

The temperature control pedestal 240 generally includes a platen 280which is generally fabricated from a thermally conductive material suchas aluminum or stainless steel, but may alternatively be comprised ofother materials, such as ceramic. The platen 280 generally has a heattransfer element 286. The heat transfer element 286 may be a fluidpassage disposed in the platen 280 or disposed in contact with a lowersurface 288 of the platen 280. Alternatively, the heat transfer element286 may be a circulated water jacket, a thermoelectric device, such as aPeltier device, or other structure that may be utilized to control thetemperature of the platen 280.

In one embodiment, the heat transfer element 286 comprises a tube 290disposed in contact with the lower surface 288 of the platen 280. Thetube 290 is coupled to a fluid source 294 that circulates a fluidthrough the tube. The fluid, for example, facility water from the fluidsource 294, may optionally be thermally regulated. The tube 290 may bedisposed in a substantially circular or spiral pattern against the lowersurface 288 of the platen 280. Typically, the tube 290 is brazed to orclamped against the lower surface 288 or adhered using a conductiveadhesive. Optionally, a conductive plate (not shown), such as a copperplate may alternatively be disposed between the tube 290 and platen 280to promote uniformity of heat transfer across the width of the platen280. An alternative embodiment of the temperature control pedestal 240is described below with reference to FIGS. 7-9.

The hoop 220 having the substrate holders 204, 206 coupled thereto maybelowered to a first position where an upper surface 292 of the platen 280is in close proximity or in contact with the substrate supported by thesecond substrate holder 206. In the first position, the platen 280 maybe used to regulate the temperature of the substrate disposed on (orproximate to) the platen 280. For example, a substrate returning fromprocessing may be cooled in the load lock chamber 122 by supporting thesubstrate during the evacuation of the load lock chamber 122 on theupper surface 292 of the platen 280. Thermal energy is transferred fromthe substrate through the platen 280 to the heat transfer element 286,thereby cooling the substrate. After cooling the substrate, thesubstrate holders 204, 206 may be raised towards the top 214 of thechamber body 202 to allow the robots 130, 114 to access to the substrateseated in the second substrate holder 206. Optionally, the holders 204,206 may be lowered to a position where the upper surface 292 is incontact or close proximity to the substrate supported by the firstsubstrate holder 204. In this position, the platen 280 may be used tothermally regulate and heat the substrate. An alternative embodiment ofthe substrate holders 204,206 is described below with reference to FIGS.10-12.

In one embodiment, the temperature control pedestal 240 includes anoptical termination 262 that is coupled to a sensor 268 for determiningthe temperature of the substrate disposed on the pedestal 240. Theoptical termination 262 allows optical information to be provided to thesensor 268 via an optical conduit InposelstartInposelend264, such as afiber optic cable. The optical termination 262 may include a window,filter, optical transfer device. One embodiment of an opticaltermination 262 is illustrated in FIG. 9, which is described in greaterdetail below.

In one embodiment, a plurality of lamps 260 is disposed in the heatermodule 270 to generate heat for thermal processing the substrate whileon the pedestal 240. In one embodiment, the lamps 260 are quartz halogenlamps providing infrared radiation having a wavelength between about 700nm and about 14000 nm. The infrared radiation generated from the lamps260 may provide heat to the substrate and increase the substratetemperature up to about 500 degrees Celsius. Generally, the wavelengthof the sensor 268 is selected to have a high change in transmittancethrough the materials and/or films being heated in the range oftemperature for which measurement is sought, for example, a temperatureof a thermal process endpoint.

In one embodiment, the sensor 268 is an InGaAs diode sensor adapted tomeasure a substrate temperature range between 100 degrees Celsius andabout 500 degrees Celsius. The sensor 268 is optically aligned with theoptical transfer device and the filter. The optical transfer device isdisposed in the pedestal 240 between an end of the optical conduit 264and the substrate. The optical conduit 264 detects collected energypassing through substrate and optical transfer device to the filter. Thefilter is adapted to filter the signal collected from the opticaltransfer device and only provides IR light with a desired wavelength tothe sensor 268.

In one embodiment, the optical transfer device, such as a collimator,has an aperture selected to allow energy to enter the optical conduit264 which is incident to the substrate at a predefined angle selected tominimize the entry of scattered energy and other noise into the conduit264. For example, the selected angle of the optical transfer device onlyallows light passing through the substrate at within a cone defined bythe angle to be collected, and prevents light incident at to thesubstrate at angles outside of the selected angle from entering into theoptical conduit 264. The unwanted reflected light from the chamber walland/or noise generated from the background may be prevented frominterfering with the signal entering to optical conduit 264 through theoptical transfer device and ultimately reaching the sensor 268 throughthe filter. The light energy reaching to the sensor 268 is then furtheranalyzed to calculate the temperature of the substrate 124.

In another embodiment, the optical transfer device may be a wide angleor fish-eye lens which collects and transfers more energy to the sensor268. This is particularly useful in embodiments where the substrate doesnot allow energy to pass through the substrate efficiently, thusallowing for compensation for low signal strength (e.g. poor energytransmission through the substrate.)

FIG. 4 depicts a sectional view of one embodiment of the heater module270. The heater module 270 is generally disposed on the top 214 of theload lock chamber 122. The heater module 270 may alternatively comprisevarious types of radiant heaters. In one embodiment, the heater module270 includes a housing 402 having one or more lamps 260 disposedtherein. The housing 402 generally includes sides 406 and a top 408 thatdefine an interior 430. The sides 406 are generally coupled to the topof the chamber body 202. An aperture 412 is formed in the top 408 of theheater module 270 to facilitate power connection to the lamp 260. Thelamp 402 is generally coupled to a power source 432 by a ceramic socket414.

A cooling device 416 is coupled to the socket 414 to control thetemperature of the lamps 260, thereby extending the life of the lamps260. In one embodiment, the cooling device 416 is an annular plate 418having good thermal conductivity that is thermally regulated by acirculating fluid. In one embodiment, the annular plate 418 is a copperdisk having a tube 420 brazed to the perimeter of the plate 418. Thefluid is circulated through the tube 420 from a fluid source 434,thereby regulating the temperature of the plate 418. Alternatively, thecooling device 416 may include thermoelectric devices, heat sinks, waterjackets and other devices that limit the temperature rise of the socket414.

The socket 414 is typically biased against the plate 418 to promote heattransfer therebetween. In one embodiment, a shoulder screw 422 isdisposed through the socket 414 and plate 418 and threads into the top408 of the housing 402. To accommodate thermal expansion between thesocket 414 and plate 418, one or more springs 424 may be disposedbetween a head 426 of the shoulder screw 422 and the socket 414. Thespring 424, which may be a coil, flat, belliville or other basisingdevice, maintains contact between the socket 414 and plate 418 over awide range of temperature without damaging the socket 414.

Optionally, a metrology device 428 may be disposed proximate the window250. In one embodiment, the metrology device 428 may be a residual gasanalyzer (RGA). The RGA detects the exhaust gases in the load lockchamber 122 and indicates the ions and species included in the exhaustgas released from the substrate surface. The released exhaust gas ionsand species reflect the amount of halogen-containing residues remainingon the substrate surface, thereby determining an end point for thehalogen-containing residue removal process. In another embodiment, themetrology device 428 may be other types of optical end point detectionsystem that facilitates for determination of an end point for thehalogen-containing residue removal process. Alternatively, the metrologydevice 428 may be a substrate type sensor, a substrate orientationsensor, a substrate center sensor, a substrate location sensor, a filmthickness detector, a topography detector or other device utilized todetect attributes of the substrate disposed in the load lock chamber122. Generally, the metrology device 428 is disposed proximate theheater module 270 and positioned to view the substrate through thewindow 250. Alternatively, the metrology device 428 may be disposed inthe heater module 270 or in the chamber volume 218.

Referring back to FIG. 2, in operation, the load lock chamber 122facilitates the transfer of substrates between the ambient atmosphere ofthe factory interface 102 and the vacuum atmosphere of the transferchamber 136. The load lock chamber 122 temporarily houses the substratewhile the atmosphere within the load lock chamber 122 is adjusted tomatch the atmosphere of the transfer chamber 136 or factory interface102 into which the substrate is to be transferred. For example, thefirst slit valve 244 is opened while the load lock chamber 122 is ventedto substantially atmospheric pressure to match the atmosphere of thefactory interface 102. The factory interface robot 114 transfers anunprocessed substrate from one of the FOUP 106A-B to the first substrateholder 204. The substrate subsequently transfers to the processingchambers 110, 112, 132, 128, 120 to perform an etch process. After thehalogen comprising etch process is completed, the pump passage 232 inthe load lock chamber 122 is subsequently opened and the load lockchamber 122 is pumped down to the pressure substantially equal to thepressure of the transfer chamber 136. Once the pressures within the loadlock chamber 122 and transfer chamber 136 are substantially equal, thesecond slit valve 246 is opened. The processed substrate is transferredto position on the second substrate holder 206 by the transfer robot 130in the load lock chamber 122. The second slit valve 246 is closed oncethe blade of the transfer robot 130 is removed.

During halogen-containing residue removal process, the second substrateholder 206 may be raised the processed substrate toward the heatermodule 270 to increase heating efficiency, thereby converting thehalogen-containing residues to non-volatile compounds that may be pumpedout of the load lock chamber 122. During the removal process, one ormore process gases may be supplied into the load lock chamber 122 topromote halogen removal as further discussed below. After thehalogen-containing residues on the processed substrate surface has beenpartially or totally outgassed from the substrate surface, the ventpassage 230 is opened in the load lock chamber 122 to allow the pressurein the load lock chamber 122 to raise to substantially match thepressure in the factory interface 102, thereby facilitating theprocessed substrate being transferred to the FOUPs 106A-B. Whileventing, the pedestal 240 is raised to contact the processed substraterest on the second substrate holder 206. The processed substrate is thuscooled by transferring heat through the pedestal 240 to the fluidcirculating in the tube 290. Once the pressures are matched, the firstslit valve 244 is opened to allow the factory interface robot 114 toaccess the load lock chamber 122 to remove the processed substrate fromthe second substrate holder 206 and return to one of the FOUPs 106A-B.As such, as the substrate cooling process and the load lock chamberventing process is performed simultaneously, the overall process periodand cycle time is reduced and productivity and throughput is increased.A newly unprocessed substrate from the FOUPs 106A-B may be transferredinto the load lock chamber 122 on the first substrate holder 204 as theprocessed substrate removed from the second substrate holder 206 by thefactory interface robot 114 while the slit valve 244 the load lockchamber 122 remains opened.

After completion of the substrate transfer, the first slit valve 244 andvent passage 230 are closed. The pump passage 232 is subsequently openedand the load lock chamber 122 is pumped down to the pressuresubstantially equal to the pressure of the transfer chamber 136. Oncethe pressure of the load lock chamber 122 and the transfer chamber 136are substantially equal, the second slit valve 246 is opened and thetransfer robot 130 then retrieves the newly unprocessed substrate forposition in the first substrate holder 204 for processing in one or moreof the process chambers 110, 112, 132, 128, 120 circumscribing thetransfer chamber 136 to repeatedly and consecutively perform the etchprocess and halogen-containing residue removal process as stated above.After substrate transfer is completed, the second slit valve 246 isclosed to seal the load lock chamber 122 from the transfer chamber 136as stated above.

FIG. 5 depicts a flow diagram of a method 500 for removing ahalogen-containing residue from a substrate in accordance with thepresent invention. The method 500 is configured to perform at theprocessing system 100 as described in FIG. 1. It is contemplated thatthe method 500 may be performed in other suitable processing systems,including those from other manufacturers.

The method 500 begins at step 502 by providing a substrate having alayer disposed thereon which is to be etched in the processing system100. The factory interface robot 114 transfers the substrate to beprocessed from one of the FOUPs 106A-B to the first substrate holder 204in the load lock chamber 122. The substrate may be any substrate ormaterial surface upon which film processing is performed. In oneembodiment, the substrate may have a layer or layers formed thereonutilized to form a structure, such as a gate structure. The substratemay alternatively utilize a mask layer as an etch mask and/or etch stoplayer disposed on the substrate to promote the transfer of the featuresor structures to the substrate. In another embodiment, the substrate mayhave multiple layers, e.g., a film stack, utilized to form differentpatterns and/or features, such as dual damascene structure and the like.The substrate may be a material such as crystalline silicon (e.g.,Si<100> or Si<111>), silicon oxide, strained silicon, silicon germanium,doped or undoped polysilicon, doped or undoped silicon wafers andpatterned or non-patterned wafers silicon on insulator (SOI), carbondoped silicon oxides, silicon nitride, doped silicon, germanium, galliumarsenide, glass, sapphire, metal layers disposed on silicon and thelike. The substrate may have various dimensions, such as 200 mm or 300mm diameter wafers, as well as, rectangular or square panels.

In one embodiment, the substrate transferred to the load lock chamber122 may be preheated to a predetermined temperature by the heater module270 or by the temperature controlled pedestal 240 in the load lockchamber 122. In one embodiment, the substrate may be preheated to atemperature between about 20 degrees Celsius and about 400 degreesCelsius.

At step 504, after the pressure within the load lock chamber 122 and thetransfer chamber 136 are substantially equal, the vacuum robot 130transfers the substrate to one of the processing chambers 110, 112, 132,128, 120. The substrate is etched in one of the processing chamber 110,112, 132, 128, 120 to form desired features and patterns on thesubstrate. In embodiments which the substrate has mask layers disposedon the substrate surface, the etch process etches the mask layerssimultaneously while forming the desired features and patterns.

In one embodiment, the substrate is etched in one of the processingchambers 110, 112, 132, 128, 120 by supplying a gas mixture having atleast a halogen-containing gas. Suitable examples of halogen-containinggas include, but not limited to, hydrogen bromide (HBr), chlorine (Cl₂),carbon tetrafluoride (CF₄), and the like. In an exemplary embodimentsuitable for etching polysilicon, the gas mixture supplied to theprocessing chamber 110, 112, 132, 128, 120 provides a gas mixtureincluding hydrogen bromide (HBr) and chlorine (Cl₂) gas at a flow ratebetween about 20 sccm and about 300 sccm, such as between 20 sccm andabout 60 sccm, for example about 40 sccm. The hydrogen bromide (HBr) andchlorine (Cl₂) gas may have a gas ratio ranging between about 1:0 andabout 1:30, such as about 1:15. An inert gas may be supplied with thegas mixture to the processing chamber 110, 112, 132, 128, 120. Suitableexamples of inert gas may include nitrogen (N₂), argon (Ar), helium (He)and the like. In one embodiment, the inert gas, such as N₂, may suppliedwith the gas mixture at a flow rate between about 0 sccm and about 200sccm, such as between about 0 sccm and about 40 sccm, for example about20 sccm. A reducing gas, such as carbon monoxide (CO) may be suppliedwith the gas mixture. The plasma power for the etch process may bemaintained between about 200 Watts and about 3000 Watts, such as about500 Watts and about 1500 Watts, for example about 1100 Watts, and thebias power may be maintained between about 0 Watts and about 300 Watts,such as about 0 Watts and about 80 Watts, for example about 20 Watts.The process pressure may be controlled at between about 2 mTorr andabout 100 mTorr, such as between about 2 mTorr and about 20 mTorr, forexample about 4 mTorr, and the substrate temperature may be maintainedat between about 0 degrees Celsius and about 200 degrees Celsius, suchas between about 0 degrees Celsius and about 100 degrees Celsius, forexample about 45 degrees Celsius.

During etching process, the etched materials may combine with thecomponents of the etchant chemistry, as well as with the components ofthe mask layers, if any, and by-products of the etch process, therebyforming halogen-containing residues. In one embodiment, the materials onthe substrate to be etched may include photoresist layer, hard masklayer, bottom anti-reflective coating (BARC), polysilicon, crystallinesilicon, gate oxide, metal gate, such as Titanium nitride (TiN), andhigh-k materials, such as aluminum oxide (Al₂O₃), hafnium containingoxide. Suitable examples of hard mask layer include silicon nitride,TEOS, silicon oxide, amorphous carbon, and silicon carbide. Thehalogen-containing residues deposit on the surfaces of the substrate.The halogen-containing residue may release (e.g., outgas) gaseousreactants, such as bromine (Br₂), chlorine (Cl₂), hydrogen chloride(HCl), hydrogen bromine (HBr) and the like, if exposed to atmosphericpressures and/or water vapor. The release of such reactants may causecorrosions and particle contamination of the processing apparatus andfactory interfaces during substrate transfer, such as the vacuum-tightprocessing platform 104 and the factory interface 102 as described inFIG. 1. In embodiments where metallic layers, such as Cu, Al, W, areexposed to the substrate surface, the metallic layer may be corroded bythe released gaseous reactants if they are not removed by the inventiveprocess described below, thereby adversely deteriorating the performanceof devices formed on the substrate.

Halogens may also be present on the surface of substrates that areprocessed in a vacuum environment in a manner other than etching.Therefore, it is contemplated that halogens may be removed from thosesubstrates using the method and apparatus described herein.

At step 506, the processed (e.g., etched) substrate is transferred tothe load lock chamber 122 to remove the halogen-containing residues fromthe substrate generated during step 504 prior to exposure to atmosphericconditions or water vapor in the factory interface or other location.After etch processing, the vacuum robot 130 in the transfer chamber 136transfers the etched substrate from one of the processing chambers 110,112, 132, 128, 120 to the second substrate holder 206 in the load lockchamber 122.

At step 508, a thermal treatment process is performed on the etchedsubstrate to remove the halogen-containing residues on the etchedsubstrate surface. The etched substrate held by the second substrateholder 206 raises the substrate 124 toward the heater module 270,thereby increasing the intensity of heat transfer to the substrate. Theheat from the heater module 270 causes the temperature of the surface ofthe substrate to rise, thereby causing halogen-based reactants disposedon the etched substrate surface to be released and/or outgassed. Theheater module 270 heats the substrate to a temperature between about 20degrees Celsius and about 400 degrees Celsius, such as between about 150degrees Celsius and about 300 degrees Celsius, for example about 250degrees Celsius, at between about 5 seconds and about 30 seconds. Therapid heating of the substrate by heater module 270 allows thehalogen-containing residues on the etched substrate to be removedwithout increasing process cycle time which would be encountered if theresidues were removed in one if the processing chambers. In oneembodiment, the substrate may be heated by the heater module 270 at apredetermined time period until the halogen-containing residues on theetched substrate are removed therefrom. The time or endpoint may bedetermined using the metrology device 428. The etched substrate may beheated at a temperature between about 150 degrees Celsius and about 300degrees Celsius, such as 250 degrees Celsius for between about 10seconds to about 120 seconds, such as between about 30 seconds to about90 seconds.

In one embodiment, a gas mixture may be supplied from the gas source 252to the load lock chamber 122 while heating the etched substrate. Theetched substrate is exposed to and reacts with the gas mixture. The gasmixture converts the outgassed halogen-based reactants intonon-corrosive volatile compounds that are pumped out of the load lockchamber 122. The gas mixture may include an oxygen-containing gas, suchas O₂, O₃, water vapor (H₂O), a hydrogen-containing gas, such as H₂,forming gas, water vapor (H₂O), alkanes, alkenes, and the like, or aninert gas, such as a nitrogen gas (N₂), argon (Ar), helium (He), and thelike. For example, the gas mixture may include oxygen, nitrogen, and ahydrogen-containing gas. In one embodiment, the hydrogen-containing gasis at least one of hydrogen (H₂) and water vapor (H₂O). In embodimentswhich mask layers is present on the substrate, the mask layers may besimultaneously removed with the halogen-containing residues, e.g., themask is stripped of the photoresist in the load lock chamber.

In one embodiment, the gas mixture may be supplied at a flow ratebetween about 100 sccm and about 5000 sccm, such as between about 200sccm and about 1000 sccm, for example about 300 sccm. Alternatively, thegas mixture, for example, may be an O₂ and N₂ gas mixture supplied at agas ratio between about 1:1 and about 20:1, such as between about 10:1.The pressure of the load lock chamber 122 may be maintained at betweenabout 10 mTorr and about 5000 mTorr, such as, between about 100 mTorrand about 1000 mTorr, for example, about 300 mTorr. In embodiments wherethe halogen-containing residues are mostly chlorine-based residuesresulting from use of chlorine-based etching chemistry, the gas mixturemay be oxygen gas (O₂) and/or hydrogen containing gas, such as watervapor (H₂O) and/or H₂. The oxygen gas (O₂) may be supplied at a flowrate at between about 100 sccm and about 5000 sccm and hydrogencontaining gas, such as water vapor (H₂O) and/or H₂ may be supplied at aflow rate at between about 100 sccm and about 3000 sccm. Alternatively,the oxygen gas (O₂) and hydrogen containing gas, such as water vapor(H₂O) and/or H₂, may be supplied at a ratio between about 200:1 andabout 1:1, such as about 150:1 and about 5:1. Alternatively, the gasmixture may be an oxygen gas or a pure hydrogen containing gas, such aswater vapor (H₂O). A residual gas analyzer (RGA), such as the metrologydevice 428 as described in FIG. 4, may be utilized to detect theremaining halogen-containing residues on the etched substrate surface.

In an alternative embodiment, the gas mixture may be provided to theinterior of the load lock chamber 122 through a remote plasma source,such as the remote plasma source 248 in FIG. 2. The remote plasma sourceionizes the gas mixture. The dissociated ions and species promote theconversion of the outgassed halogen-based reactants into non-corrosivevolatile compounds, thereby increasing the removal efficiency of thehalogen-containing residues from the etched substrate surface. In oneembodiment, the remote plasma source may provide a plasma power atbetween about 500 Watts and 6000 Watts. In embodiments where the plasmais present, an inert gas, such as Ar, He or N₂, may be supplied with thegas mixture.

Optionally, a step 509 may be performed wherein the substrate isreturned to one of the processing chamber 110, 112, 132, 128, 120 of thesystem for additional processing prior to removing from the vacuumenvironment. The substrate, after the halogen removal process of step508, will not introduce halogens into the processing chambers duringsubsequent processing, thereby preventing damage to the processingchambers.

At step 510, the temperature control pedestal 240 is raised to contactthe etched substrate supported on the second substrate holder 206 afterthe halogen residue removal step 508 to cool the substrate to a desiredtemperature. The etched substrate is cooled by transferring heat throughthe pedestal 240 to the fluid circulating in the tube 290. In oneembodiment, the etched substrate may be cooled to a temperature rangingbetween about 10 degrees Celsius and about 125 degrees Celsius thatallows the etched substrate returning to the FOUPs 106A-B withoutcausing damage to the FOUPs 106A-B.

Alternatively, at step 510 the temperature control pedestal 240 coolsthe etched substrate supported on the second substrate holder 206 afterthe halogen residue removal step 508 to cool the substrate to a firsttemperature which is too great to be placed in the FOUP, for example, atemperature greater than about 125 degrees Celsius. Alternative step 510would include removing the still hot substrate from the load lockchamber 122 and placing substrate in the substrate holder 182 for apredetermined period of time until the substrate reaches a secondtemperature which is low enough to be placed in the FOUP, for example, atemperature less than about 125 degrees Celsius. In one embodiment, thesubstrate is set in the substrate holder 182 to cool for about 20-30second.

While cooling the substrate at step 510, the load lock chamber 122 maybe simultaneously vented in preparation for the subsequent substratetransfer process at step 512 to minimize process cycle time. Once thepressures of the load lock chamber 122 and the factory interface 102 arematched, the first slit valve 244 is opened to allow the factoryinterface robot 114 to access the load lock chamber 122 to remove theetched substrate from the load lock chamber 122 and return to one of theFOUPs 106A-B. A newly unprocessed substrate from the FOUPs 106A-B may betransferred into the load lock chamber 122 on the first substrate holder204 while the etched substrate is removed from the second substrateholder 206, thereby repeatedly and consecutively processing substratesas indicated by the loop 514 depicted in FIG. 5.

FIG. 6 depicts a sectional view of one embodiment of a window 600 thatmay be utilized in the load lock chamber 122 of FIG. 2, among othervacuum chambers. The window 600 includes a ring 602 coupled to a convexmember 604. The ring 602 and the convex member 604 may be fabricatedfrom clear quartz or other suitable material. In one embodiment,peripheral portions of the ring 602 may be fabricated from frosted whitequartz or other suitable opaque material to shield an underlying o-ringfrom light emitted from the plurality of lamps 260, thereby reducingdegradation from radiation heating on the o-ring. The window 600 may befire polished prior to annealing. In one embodiment, the ring 602 isfused to the convex member 604 to provide a vacuum tight sealtherebetween.

The ring 602 generally includes an inside edge 612, an outside edge 606,a top 610 and a bottom 608. The inside edge 612 includes a lip 614 thatextends radially inward between upper and lower sections 612 a, 612 b ofthe edge 612. The upper and lower sections 612 a, 612 b of the edge 612have a large radius that provides structural support for the lip 614.The radius of the lower section 612 b may be greater than that of theupper section 612 a. The lip 614 is angled upward and inward andprovides a fastening surface for coupling the ring 602 to the convexmember 604. In one embodiment, the bottom 608 is in sealing contact withan o-ring to prevent leakage past the window 600.

The convex member 604 includes a top 616 and a bottom 618 joined at anouter edge 620. The outer edge 620 is fused or otherwise sealinglyfastened to the lip 614 of the ring 602. The curvature of the top 616and the bottom 618 and thickness of the convex member 604 are selectedto withstand vacuum levels commonly utilized in load lock chambers ofsemiconductor processing systems. In one embodiment, the top 616 of theconvex member 604 extends to an elevation beyond the top 610 of the ring602.

FIG. 7 depicts a sectional view of one embodiment of a temperaturecontrol pedestal 700 that may be utilized in the load lock chamber 122of FIG. 2, among other vacuum chambers. The temperature control pedestal700 includes a base 702 and a cooling coil 704. The base 702 may befabricated from aluminum or other suitable material, and has a topsurface 706 for supporting the substrate, a bottom surface 708 and anouter wall 712.

The outer wall 712 defines the outer diameter of the base 702 and has asmall projection 714 extending therefrom. The projection 714 may be inthe form of a continuous or intermittent lip or other geometricprojection that is suitable for supporting the temperature controlpedestal 700 on a ledge 780 formed in the chamber body 202. Theprojection 714 is utilized to thermally isolate the base 702 from thechamber body 202. The projection 714 enables the temperature controlpedestal 700 to be efficiently maintained at or below 25 degrees Celsiuswhile the walls of the chamber body 202 are maintained in excess of 50degrees Celsius, for example, at a temperature differential of about 25degrees Celsius. The ability to maintain the temperature differentialallows for the chamber body 202 to be held at an elevated temperaturethat minimizes the deposition of material thereon, while still allowinggood cooling of the substrate positioned on the pedestal 700. In oneembodiment, the projection 714 is a substantially triangular form.

The top surface 706 of the temperature control pedestal 700 includes araised rim 716 and a plurality of substrate spacers 718 (shown in FIG.8). The raised rim 716 is positioned at the outer wall 712 of the base702. The raised rim 716 may be in the form of a continuous orintermittent lip or other geometric projection that is suitable formaintaining and/or centering the substrate on the top surface 706. Thesubstrate spacers 718 project a small distance from the top surface 706as not to overly hinder the heat transfer between the top surface 706and the substrate positioned on the spacers 718. In one embodiment, thesubstrate spacers 718 are in the form of domes.

The coil 704 is housed in a recess 720 formed in the bottom surface 708of the base 702. The coil 704 may be secured in the recess 720 by apotting material 710. Alternatively, the coil 704 may be secured in therecess 720 by fasteners, a clamp or other means that allows good heattransfer between the coil 704 and base 702.

The base 702 of the temperature control pedestal 700 also includes amounting feature 730 configured to accept an optical termination 262.The optical termination 262 facilitates securing optical informationthat may be utilized to determine the temperature of the substratepositioned on the temperature control pedestal 700. The mounting feature730 may be positioned offset from the centerline of the base 702.

FIG. 9 is a partial sectional view illustrating one embodiment of theoptical termination 262 mated with the mounting feature 730 of the base702. The optical termination 262 includes a window 902, an optionalfilter 904, an optical transfer device 906 and an adapter 908. Theoptical transfer device 906 may be an optical collimator or a lens, suchas a wide angle or fish-eye lens.

The adapter 908 retains at least the optional filter 904 and opticaltransfer device 906 to the base 702. In one embodiment, the mountingfeature 730 includes an aperture 930 which opens into a stepped recess932 formed on a bottom surface 934 of the recess 720. An o-ring gland936 is formed in a bottom surface 934 of the stepped recess 932. The topsurface 706 of the base 702 may include a countersink 940 which opensinto the aperture 930 to facility light entry. The countersink 940 has acountersink angle larger than 10 degrees. In one embodiment, thecountersink angle is 45 degrees or greater. A wide countersink anglepromotes capture of large amounts of light for increased signalstrength. Substrates comprising light-absorbent materials, such ascarbon films may absorb a substantial amount of light, thus reducing theamount of light entering the aperture 930. The wide countersink angleadvantageously enables the entry of additional light traveling throughthe substrate into the aperture 930, thus resulting in an increasedsignal strength which can compensate for poor light transmission throughthe substrate. The aperture 930 may also include a rough surfacefeature, such as a plurality of ridges 942 formed in wall of base 702defining the aperture 930, to improve the capture of desired light. Theplurality of ridges 942 reduces the reflectance of light within theaperture 930.

The optical termination 262 is screwed or clamped to the base 702 suchthat o-rings disposed in the gland 936 of the base 702 and in a gland944 of the adapter 908 creates a gas-tight seal around the window 902spanning the aperture 930. The window 902 may be quartz, sapphire orother suitable material.

The optical termination 262 includes a center passage 950 in which theend of the optical conduit 264, the optional filter 904 and the opticaltransfer device 906 are secured. In one embodiment, the center passage950 includes a first threaded section 952 which engages the opticaltransfer device 906 in a position proximate the window 902.

The close position of the optical transfer device 906 to the aperture930 provides a greater capture angle for incident light. The end of theoptical conduit 264 may be secured to the adapter 908 via clamps,fasteners that engage threaded holes in the adapter 908 or the end ofthe optical conduit 264 may thread directly into the center passage 950of the adapter 908. In another embodiment, the optical filter 904 iscoupled at the end of the optical conduit 264. The optical filter 904 isengaged to a diode sensor, the sensor capable of reading opticalinformation that may be utilized to determine the temperature of thesubstrate positioned on the temperature control pedestal 700.

Also shown in FIG. 9 is an anodized coating 990 that covers the topsurface 706 of the base 702, aperture 930 and portion of the bottomsurface 934 of the stepped recess 932 up to the gland 936.

FIGS. 10-11 depict a perspective and top plan views of one embodiment ofa substrate holder 1000 that may be utilized in the load lock chamber122 of FIG. 2, among other vacuum chambers. The substrate holder 1000may be fabricated from aluminum or other suitable material. Thesubstrate holder 1000 is designed to minimize contact with thesubstrate. The substrate holder 1000 includes an arc-shaped body 1002having a mounting flange 1004 and two support flanges 1006. The mountingflange 1004 extends radially outward from an outer edge 1008 of theholder 1000. The mounting flange 1004 includes two dowel pin holes 1010,a mounting hole 1012 and a mounting slot 1014 to facilitate mounting ofthe holder 1000 to the hoop 220 (shown in FIG. 2) or other supportstructure. The hole 1012 and slot 1014 provides greater tolerancesbetween the hoop 220 and holder 1000, while the dowel pin holes 1010allow for precise orientation and location of the holder 1000 within theload lock chamber 122.

Each support flange 1004 extends radially inward from an inner edge 1020of the holder 1000. The support flanges 1004 are positioned at oppositeends of the holder 1000.

Referring additionally to FIGS. 11 and 12, each of the support flanges1004 includes a step 1022. In an alternative embodiment, each of thesupport flanges includes a flat end. The step 1022 is recessed from atop side 1024 of the holder 1000. The step 1022 includes a landing 1026on which the substrate rests while on the holder 1000. The landing 1026may have a substantially horizontal orientation, which is alsosubstantially parallel to the top side 1024 and a bottom side 1028 ofthe holder 1000. The landing 1026 may alternatively be sloped downwardrelative to the horizon, thus having an orientation of between 2-5degrees relative to the top side 1024 of the holder 1000. The inclinedorientation of the landings 1026 allows the substrate to only contactthe holder 1000 at the very edge of the substrate, thereby minimizingpotential damage. Additionally, since the substrate solely contacts theholder 1000 on the two small landings 1026, potential damage to thesubstrate is further reduced over designs which have contact with thesubstrate along the complete length of the holder. Furthermore, theminimal contact to the substrate with the landings 1026 allows forbetter temperature control, as the bulk of the substrate is in contactor close proximity of the cooling pedestal which is thermally isolatedfrom the holders.

Each step 1022 may alternatively include a hole 1052 formed in the step1022. A contact ball 1050 is retained in the hole 1052 such that an edgeof the ball 1050 extends above the surface of the step 1022. Forexample, the contact ball 1050 may be press-fit into the hole 1052. Inone embodiment, the contact ball 1050 comprises silicon nitrate or othersuitable material having a low heat transfer rate. As the substratesolely contacts the two contact balls 1050 of the holder 1000, thermalisolation between the substrate and holder 1000 is improved, thusresulting in improved substrate temperature control and faster heatingof the substrate.

Thus, the present invention provides an apparatus for removing halogenand/or halogen-containing residues on a substrate. The apparatusadvantageously prevents substrate contamination and corrosion of exposedportions of metallic films deposited on the substrate, along withpreventing contamination and corrosion of the processing system from byreleased halogens, thereby enhancing productivity and processthroughput.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A pedestal comprising: a base comprising: an outer wall; a projectionextending radially from the outer wall; a top surface; a bottom surface;a mounting feature positioned centrally within the base, the mountingfeature having an aperture configured to accept an optical terminationfrom the top surface; a recess formed on the bottom surface of the base;and a countersink formed on the top surface of the base, the countersinkconfigured to permit the entry of light into the aperture; and a coolingcoil disposed in the recess adjacent the bottom surface of the base. 2.The apparatus of claim 1, wherein the base comprises: a window sealingthe aperture.
 3. The apparatus of claim 1, wherein the base furthercomprises: a lens disposed within the aperture formed through the base.4. The apparatus of claim 3, wherein the base further comprises: anoptical termination disposed in the aperture and coupled to the base,the optical termination aligned to receive optical transmissions throughthe aperture.
 5. The apparatus of claim 3, wherein the base furthercomprises: a raised rim extending from the top surface of the base. 6.The apparatus of claim 3, wherein the base further comprises: aplurality of domes projecting from the top surface of the base.
 7. Theapparatus of claim 1, wherein the countersink has an angle greater thanabout 45 degrees.
 8. A substrate holder comprising: an arc-shaped bodyhaving a mounting flange extending radially outward from an outer edgeof the holder; two support flanges positioned at opposite ends of thebody, each support flange extending radially inward from an inner edgeof the body and having a substrate support step recessed from a top sideof the body, each substrate support step having a sloped landing.
 9. Thesubstrate holder of claim 8, wherein the sloped landing of the supportstep further comprises: a top surface, a hole formed in the top surface;and a contact ball disposed into the hole, the contact ball extendingabove the top surface.
 10. The substrate holder of claim 9, wherein thecontact ball comprises silicon nitrate.
 11. The substrate holder ofclaim 8, wherein the sloped landing extends downward relative to the topside of the body, the sloped landing having an orientation of betweenabout 2 to about 5 degrees relative to the top side of the body.